The invention relates to an apparatus and method for cleaning a probe between fluid sampling operations of the probe. More particularly, this invention concerns the external washing and drying of a probe preparatory to its use with another sample.
In sample analysis and cell sorting systems it is necessary to virtually eliminate sample contamination, while rapidly and repetitively sampling successive samples, particularly where a large number of different samples are to be processed automatically. Preferably, the apparatus should be as simple and compact as possible, as well as perform both sampling and cleaning in situ, that is in the same lateral position. Some large size sample analysis and cell sorting systems such as the DACOS.TM. Chemistry System, manufactured by Coulter Electronics, Inc., Hialeah, Fla., utilize transfer mechanisms to laterally move an axially movable, vertically oriented, sampling probe between sampling operations for cleaning to a closed bottom cleaning station. Systems that utilize an axially movable but horizontally oriented sample probe and an opened ended cleaning station, such as disclosed in U.S. Pat. No. 4,311,484, issued Jan. 19, 1982, require closed sample containers and relatively elaborate sample feeding mechanisms. Systems that do utilize an axiable movable, vertically oriented, sampling probe which do not require such transfer mechanisms and instead utilize separate movable washing-drying mechanisms and waste units, such as disclosed in U.S. Pat. No. 4,217,780, issued Aug. 19, 1980, are relatively complex in design. Furthermore, none of such systems utilizing an opened ended cleaning station is ideally suited for automatically processing a large number of samples individually contained in the separate, open, wells of a standard twenty-four or ninety-six well microculture plate such as a MICROTITER.RTM. plate. (MICROTITER is a registered trademark of Dynatech Laboratories, Inc.)